1. Field of the Invention
The present invention relates to an alignment tool for use in accurately aligning and holding in place two sections of boiler tube, so that the sections may be coupled end to end by a welding or analogous operation and particularly to a boiler tube alignment clamp.
2. Description of the Prior Art
One problem with the operation of heat exchangers is that the heat, gases, dust and substances or fluids to which they are exposed frequently leads to increased rates of corrosion resulting in damage or defects in the tubes of the heat exchanger and subsequent leakage. A conventional approach to repairing the heat exchanger is to remove a section of the damaged tube, including the defect, over some length, and to install a new replacement tube in its place. The ends of the replacement tube and the stubs of the existing tube are prepared for welding by fitting and beveling surfaces at which they will be joined. Typically, the joining is done manually using shielded metal arc welding. A tube alignment clamp assembly is required to align the ends of the replacement portion with the existing portion of boiler tube prior to welding the two ends together.
Prior art clamps are often cumbersome, sometimes expensive and difficult to use and they often do not provide a large exposed area of the boiler tube ends for welding.
Prior art U.S. Pat. No. 4,750,662, issued Jun. 14, 1988 to Kagimoto, provides a pipe clamping and alignment tool for locating and clamping pipe sections in accurate end to end alignment for welding. The device has a pair of clamping assemblies for the respective pipe sections threaded respectively on opposite-hand threads of a turnbuckle-type bolt. Each clamping assembly has a cradle for receiving the respective pipe section, a releasable U-bolt clamp for holding the pipe section on the cradle, and pairs of angled adjusting screws for engaging the pipe section and adjusting its alignment both longitudinally and laterally.
Prior art U.S. Pat. No. 4,415,188, issued Nov. 15, 1983 to Ginter, Jr., illustrates a clamping member for securing pipe portions of an automobile exhaust system. The clamping member comprises first and second generally vertically extending end flanges and a generally horizontally extending section intermediate of and interconnecting the first and second end flanges. Each of the end flanges has a cutout portion for reception of a pipe portion to be clamped therein and first and second sleeve portions adjacent opposite sides of the respective end flange for reception of the ends of a U-bolt. The first and second end flanges, the section interconnecting the first and second end flanges, and the sleeve portions are formed from a one-piece blank.
Prior art U.S. Pat. No. 4,262,943, issued Apr. 21, 1981 to Armstrong, shows a muffler clamp device that comprises a longitudinal base member, the opposite ends of which are upright and formed to seat the muffler sleeve and the connecting tail pipe end. U-bolts are provided that encircle the muffler sleeve and the connecting tail pipe end at longitudinally spaced planes. The object of this invention is to clamp the muffler sleeve and tail pipe end separately at longitudinally spaced locations to rigidly support the connecting ends relative to each other and relative to the longitudinal base member.
Prior art U.S. Pat. No. 4,936,500, issued Jun. 26, 1990 to McClure, indicates a bolt-type boiler wall tube tool in which boiler tubes in the form of a wall can be clampingly secured to retain adjacent ends of the boiler tubes forming the wall in aligned relation when connecting the ends of the boiler wall tubes by welding.
Prior art U.S. Pat. No. 5,481,793, issued Jan. 9, 1996 to McClure, puts forth a hook and bolt type boiler wall tube tool for clamping together adjacent ends at a juncture of a boiler wall tube in a boiler wall. The tool includes first and second opposing clamping members, each clamping member including a recess suitable for engaging an exterior surface of a tube and for extending across the juncture of a tube. A pair of slots which are spaced from each other and substantially aligned with the slots on the other clamping member are provided in each clamping member. The slots on the first clamping member include sloped edges terminating at an outer portion thereof. A hook-and-bolt member secures the clamping members around the tube segments. The hook-and-bolt member includes a pair of hook arms for extending through the slots of the clamping members and suitable for passing through a spacing between laterally adjacent boiler tubes. Each end of the hook arms terminates in hooked ends for engaging the sloped edges on the slots of the first clamping member. A bolt passing through threads in the handle engages a front face of the second clamping member and applies force to pull the first clamping member towards the second clamping member.
Prior art U.S. Pat. No. 4,846,391, issued Jul. 11, 1989 to McClure, concerns a boiler wall tube tool in which boiler tubes in the form of a wall can be clampingly secured to retain adjacent ends of the boiler tubes forming the wall in aligned relation when connecting the ends of the boiler tubes, which form the wall, when being joined by welding.
What is needed is a boiler tube clamp to secure together two boiler tube ends for welding the ends together, which boiler tube clamp creates a secure clamping of the boiler tube ends together while still providing a maximum exposed area of the circumference of the boiler tube ends for welding them together, is easy to use, and adjustable to fit a variety of boiler tube sizes.